Transmission of pressure waves such as acoustic radiation towards a target and receipt of the scattered radiation may be managed by a modern acoustic-imaging system, which may take a variety of forms. For instance, acoustic imaging is an important technique that may be used at different acoustic frequencies for varied applications that range from medical imaging to nondestructive testing of structures. The techniques generally rely on the fact that different structures have different acoustic impedances, allowing characterization of structures and their interfaces from information embodied by the different scattering patterns that result. While most applications use radiation reflected from structures, some techniques also make use of information in transmitted patterns.
For example, many modern systems are based on multiple-element array transducers that may have linear, curved-linear, phased-array or similar characteristics, and which may be embodied in an acoustic probe. Summing the contributions of the multiple transducer elements comprised by a transducer array allows images to be formed.
It is sometimes desired to analyze certain portions of received pressure waves relative to other portions of pressure waves. In the case of ultrasound probes, for instance, the failure of a small number of elements in a given array, or a few defective receive channels in the acoustic system itself, may not be readily perceptible to users because of the averaging effect of summing many elements to form an acoustic beam. But the failure of even a small number of elements or receive channels can significantly degrade the performance of acoustic imaging systems, notably in certain modes of operation like those known as “Doppler” or “near-field” imaging modes.
Thus, appliances have previously been developed to analyze received acoustic waves to determine whether certain portions of the waves indicate that particular corresponding transducer elements (e.g., that generated such certain portions of the waves) are defective. However, such existing appliances are relatively complex, based on the direct electrical connection to probe elements or system channels. The development of two-dimensional “matrix array” probe technology has made the necessary reverse engineering of even a small number of probe and system models to support direct electrical-connection-based testing complex and expensive. Other solutions use a sensor to detect energy emanating from a probe and to inject signals back into the ultrasound system for detection and display. Such solutions use a single sensor designed to sense elements in linear arrays, providing only a “signal” or “no signal” status relative to transmitted energy and require operator skill to scan a linear array probe for missing or nonfunctional elements.
There is thus a need in the art for convenient, inexpensive, and easy-to-use methods and appliances (e.g., sensors) for evaluating pressure waves in various contexts such as ultrasonic probes and systems, both for acoustic power output as well as for other issues such as failed elements or channels, particularly to evaluate two-dimensional array probes and systems.